1- Bromonaphthalene, oxidation

Chemical/Physical. An aqueous solution containing chlorine dioxide in the dark for 3.5 d oxidized naphthalene to chloronaphthalene, 1,4-dichloronaphthalene, and methyl esters of phthalic acid (Taymaz et ah, 1979). In the presence of bromide ions and a chlorinating agent (sodium hypochlorite), major products identified at various reaction times and pHs include 1-bromonaphthalene, dibromonaphthalene, and 2-bromo-l,4-naphthoquinone. Minor products identified include chloronaphthalene, dibromonaphthalene, bromochloronaphthalene, bromo-naphthol, dibromonaphthol, 2-bromonaphthoquinone, dichloronaphthalene, and chlorodibromo-naphthalene (Lin et ah, 1984). 

The reaction in Scheme 5.2 proceeds through the formation of the 1-bromonaphthalene anion-radical, which rapidly converts into the naphthyl radical. Thiophenolate intercepts the naphthyl radical and forms the anion-radical of l-(phenylthio)naphthalene. The reaction takes place in the preelectrode space. It competes with the formation of the unsubstituted naphthalene. The debromi-nation is a result of hydrogen abstraction from the solvent SolH by the naphthyl radical. The unreacted 1-bromonapthalene oxidizes the l-(phenylthio)naphthalene anion-radical formed. This leads to the neutral l-(phenylthio)naphthalene and the anion-radical of 1-bromonaphthalene. The reaction takes place in the bulk solution and is the key-point for the chain propagation. 

Hudhcky, T., Endoma, M.A.A. and Butora, G. (1996a) New chiral synthons from the microbial oxidation of bromonaphthalenes. Tetrahedron Asymmetry, 7,61-68. 

Stereoselective synthesis of perylenequinones. Synthesis of the symmetrical perylenequinone phleichrome (4) has been effected by coupling of two identical naphthalene units to provide a binaphthol, which is then oxidized to a perylenequinone. Thus the bromonaphthalene 1 on halo-lithium exchange (f-BuLi) followed by reaction of anhydrous FeCl3 dimerizes to two optically active binaphthyls, (+)-and (— )-2, with 3 1 diastereoselectivity. 

Replacement of the diazo group by hydrogen has been reported for a number of diazo oxides. For example, the diazo oxide from 2-nitro-4-aminophenol yields o-nitrophenol in 53% yield,42 - 43 and that from 1-amino-2-hydroxy-6-bromonaphthalene-4-sulfonic acid gives XV in approximately 50% yield.44... 

The syntheses of benzo[e] and benzo[g]indoles have been performed by reaction of 2-amino-1-bromo or l-amino-2-bromonaphthalene with the anion of pinacolone (67% and 82% yields, respectively). The reaction with the anion CH2COCH(OMe)2, affords the 2-formyl indoles (52% and 65% yields, respectively), which can be oxidized to the corresponding acids [90]. 

In the dehalogenation of 4-chlorobiphenyl, 1-chloro- and 1-bromonaphthalene, 9-chloro- and 9-bromoanthracene and 4-chlorobenzonitrile, diethyl sulphide has been used as electron donor397. The involvement of radical anions in these reactions is evidenced by the incorporation of deuterium into the products when the reactions were performed in acetonitrile-deuterium oxide. Lithium diisopropylamide in hexane or tetrahydrofuran398 and sodium methyl siliconate (MeSi03Na3)399 have also been used as electron transfer reagents in the photodehalogenation of 4-chlorobiphenyl. 

Table A4.3 Contact angles of several liquids on oxides, minerals and metalloids. Abbreviations a = advancing angle r = receding emgle a-BN = alpha-bromonaphthalene DIM = diiodomethane or methylene iodide. In the references methodical information can be found and there the mecining of other (liquid) will also be explained.

By this method, 1-bromonaphthalene affords 1-naphthonitrile in 94% yield after refluxing for 4 hrs. with pyridine as solvent the reaction mixture is heated in an oil bath at 215-225° for 15 hrs., and the yield is 82-90%. Efficient procedures for liberating the nitrile from the cuprous halide complex involve pouring the brown reaction mixture into an aqueous solution of ferric chloride (oxidizes Cu+ to Cu ", which forms no complex), ethylenediamine (forms complexes with Cu+ and Cu " ), or sodium cyanide (forms soluble sodium cuprocyanide). The higher-boiling N-methyl-2-pyrrolidone (b.p, 202°) is also satisfactory, but is more expensive. 

Other polycyclic aromatic hydrocarbons such as phenanthrene, anthracene, and fluoranthene are converted to the corresponding quinones on oxidation with CAS. Whereas 1-methylnaphthalene gives 1-naphthaldehyde under the conditions, 1-phenyl- and 1-bromonaphthalene react to form some 2-substituted naphthoquinones through an interesting rearrangement (eq 2). ... 

Starting from 2-hydro yphenylboronic acid and o-bromobenzaldehyde or o-bromonaphthalene carboxaldehyde derivatives as substrates, a number of 6H-benzo[c]chromene-6-ones, 51f-naphtho[l,2-c]chrome-5-ones, and 6H-naphtho[2,l-c]chromene-6-one were synthesized in good yields (Scheme 3.44a). The overall transformation consists of three reactions Suzuki-Miyaura cross-coupling, hemi-acetal formation, and oxidation. By combining 6-diazo-2-cyclohexenone and 2-iodo methylbenzoate as substrates, benzo[c]chromen-6-ones were produced in good yields as well... 

Similar to the reaction with urea anion, the photostimulated reaction of 1-bromonaphthalene with selenobenzamide and selenourea anions afforded methyl-1-naphthyl selenide after quenching the reaction with Mel [68]. The Se nucleophile can be formed by reaction of Se and Na metals in liquid ammonia and reacts under irradiation with Phi to give (PhSe) (78%) after oxidation of the PhSe" ions formed [69]. The reaction of PhSe" or PhTe" with ArX under irradiation straightforward and scrambled products are obtained and depends on the ArX employed [59, 70]. 

We have found that the oxidative addition of Mn to 2-bromonaphthalene was completed at rt in 1 h. The resulting 2-naphthylmanganese bromide was followed by a coupling reaction with benzoyl chloride to give the 2-naphtho-phenone in the presence of a Cu catalyst (Table 8.5, entry 7). It was observed... 

Cervenka and Merrall [72] investigated the application of acidic dehydration of ethylene oxide-propylene oxide condensates in bromonaphthalene in the presence of p-toluene sulfonic acid to the elucidation of the molecular structure and monomer sequence of these polymers. Gas chromatography was used to determine dehydration products. 

The oxidative addition of aryl halides, ArX, to [Co(PPhj) (Me)] yields both ArAr and ArMe (Ar=4-MeCgH ), but exclusively ArMe when Aral- and 2-bromonaphthalene and 4-bromobiphenylThe interference of the decomposition of the triphenylphosphine ligand in... 

A suspension of cuprous oxide promotes nucleophilic substitution in aprotic polar solvents at e. g. 150-200°. Effective nucleophiles are the anions ArO , AlkO , ArS , AlkS , CN", I, Br , and Gl phenols and thiols may be used in place of their salts.—E Thioethers from halides. 1-Bromonaphthalene and Na-thio-phenoxide heated 24 hrs. at 153° in dimethylformamide containing CugO -> 1-phenylthionaphthalene. Y 99%. F. e. s. R. G. R. Bacon and H. A. O. Hill, Soc. 1964, 1108. 

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